TECHNICAL FIELD
[0001] The subject matter described herein relates to implementing transcoder-free operation
in a telecommunications network. More particularly, the subject matter described herein
relates to methods, systems, and computer program products for implementing transcoder-free
operation in a media gateway.
BACKGROUND ART
[0002] In telecommunications networks, codecs are devices that encode and decode voice signals
transmitted over the network. Conventionally, uniform pulse code modulation (PCM)
was used to encode voice sent over the telecommunications network. Uniform PCM involves
sampling voice signals at a rate of 8,000 samples per second and 8 bits per sample,
resulting in a 64 kbps codec rate. More recently, in mobile communications networks,
adaptive modulation rate (AMR) codecs have been developed in which encoding and decoding
rates change during a call. AMR is used to reduce the bandwidth used by voice calls.
[0003] One problem associated with using AMR codecs or other different types of codecs is
that transcoding may be required when the source and destination devices use incompatible
codecs. Transcoding is a process by which a voice signal encoded according to one
rate and encoding standard is converted to another rate and another encoding standard.
One problem with performing transcoding is that it can introduce latency and degradation
in the voice signal being transmitted.
[0004] Figure 1 is a block diagram illustrating transcoders performing transcoding of a
speech signal in a telecommunications network. Referring to Figure 1, a first transcoder
100 receives an AMR voice signal at an IuUP or NbUP interface of a 3GPP UMTS network.
Transcoder
100 performs atranscoding operation by which the AMR voice signal is converted to PCM
and forwards the signal to transcoder
102. Transcoder
100 introduces latency and voice degradation into the signal. The latency and voice degradation
introduced by transcoder
100 is indicated by T
1 in Figure 1.
[0005] Transcoder
102 receives the PCM signal from transcoder
100 and performs a second transcoding operation, converting the PCM signal to AMR rate
1, the same AMR rate received by the first transcoder. Transcoder
102 introduces further latency and voice quality degradation into the signal. The latency
and voice quality degradation introduced by transcoder
102 is indicated by T
2 in Figure 1. In the example illustrated in Figure 1, because the ingress and egress
AMR rates are equal, transcoding is unnecessary. However, transcoding is performed
because no intelligence exists in the network illustrated in this example to eliminate
transcoding.
[0006] In order to avoid the difficulties associated with transcoding, methods for transcoder-free
operation have been developed. Transcoder-free operation refers to operation in which
a connection that is established between telecommunications endpoints, such as mobile
telephones, that have compatible codecs where the connection does not use transcoders.
Figure 2 is a block diagram of a conventional transcoder-free operation implementation
developed by the assignee of the present application for use in a media gateway, referred
to as the SanteraOne™ media gateway. Referring to Figure 2, media gateway
200 includes a plurality of packet network interfaces
202 for interfacing core networks, such as radio network control (RNC)/core network
205, that interface with voice over IP devices, such as mobile phones
204, an ATM switching fabric
206, voice servers
208, a TDM matrix
210, and TDM network interfaces
212. ATM switching fabric
206 establishes connections between packet network interfaces
202 and voice servers
208. Voice servers
208 perform voice processing functions, such as transcoding, encoding, and decoding.
In the illustrated example, each voice server
208 includes a DSP
214 that implements a codec function. TDM matrix
210 switches TDM channels between TDM network interfaces
212 and voice servers
208. TDM matrix
210 also includes an HDLC bus
216 that interconnects DSPs on different voice servers. TDM network interfaces
212 interface with TDM based telecommunications endpoints.
[0007] In the example illustrated in Figure 2, in order to implement a transcoder-free connection,
two codecs and two HDLC channels are used. That is, one DSP
214 on voice server
108 monitors the rate of an encoder used by a first telecommunications endpoint and the
other DSP
214 on a separate voice server card monitors the encoding rate being used by the other
endpoint. Rates and rate changes are communicated between the codecs using the HDLC
connections. No transcoding is performed by either voice server because the ingress
and egress codec rates are the same.
[0008] One problem associated with the transcoder-free operation of the media gateway
200 illustrated in Figure 2 it requires separate DPSs to monitor each endpoint of the
connection Another problem is that the DSPs must be interconnected using two HDLC
connections. Establishing each HDLC connection requires complex connection establishment
procedures.
[0009] Document
US 2005/0124299 A1 discloses a communication system for distribution of a bearer format type information
among network elements located along a bearer path of a communication session. The
bearer format type information informs of bearer format types supported by each of
the network elements.
[0010] Document
EP 1 465 445 A1 discloses a method involving comparing information in a transmission protocol regarding
the codec mode to be used in the connections in a switching device (MSC) for at least
two connection parts of an end-to-end connection to a media gateway. If the information
is different then signaling to Trans Break Equipment (TBE) is carried out. Matching
codec mode information for the connection parts is determined by the Trans Break Equipment.
[0011] Document TS 23 153: "Draft TS 23.153 Version 2.1.0", 3GPP Draft, vol. CN WG4, 2001
discloses general handling procedures for media gateway control procedures for codec
handling.
[0012] Document
US 2005/0076108 A1 discloses that packets associated with a call/session are received and processed
at a media gateway. For the first few received media packets associated with a session,
the media gateway uses various unique methods to learn the actual source IP address
and UDP port assigned to the remote communication terminal by its customer-premises
Network Address Translators (NATs) to the media flows of the current session. After
the remote IP and UDP are learned, the media gateway reconfigures its firewall filtering
function to check both the dynamically learned remote IP and UDP and the locally assigned
IP and UDP of the current session.
[0013] Thus, in light of the difficulties associated with providing transcoder-free operation
in media gateway, there exists a need for improve methods, systems, and computer program
products for providing transcoder-free operation in a media gateway.
SUMMARY
[0014] According to one aspect, the subject matter described herein includes a method for
implementing transcoder-free operation in a media gateway. The method includes receiving
lists of media encoding rates and corresponding indices used by first and second endpoints
of a media stream connection. Next, it is determined whether transcoder-free operation
is possible for the media stream connection. In response to determining that transcoder-free
operation is possible, a transcoder-free connection is established in the media gateway
between the first and second media endpoints using a single digital signal processor
in a first voice server to monitor and map between indices and encoding rates used
by the first and second media endpoints during the media stream connection. Establishing
a transcoder-free connection includes establishing a first connection between the
first media endpoint and the first voice server, establishing a second connection
between the second media endpoint and a second voice server, and replacing the second
connection with a third connection between the second media endpoint and the first
voice server.
[0015] The subject matter described herein may be implemented using a computer program product
comprising computer executable instructions embodied in a computer readable medium.
Exemplary computer readable media suitable for implementing the subject matter described
herein include chip memory devices, disc memory devices, application specific integrated
circuits, programmable logic devices, and downloadable electrical signals. In addition,
a computer program product that implements a subject matter described herein may reside
on a single device or computing platform or maybe distributed across multiple devices
or computing platforms.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Preferred embodiments of the subject matter described herein will now be explained
with reference to the accompanying drawings of which:
Figure 1 is a block diagram illustrating transcoding in a telecommunications network;
Figure 2 is a block diagram illustrating a conventional transcoder-free operation
implementation in a media gateway;
Figure 3 is a flow chart illustrating a method for implementing transcoder-free operation
in a media gateway according to an embodiment of the subject matter described herein;
Figure 4 is a block diagram illustrating exemplary components for implementing transcoder-free
operation in a media gateway according to an embodiment of the subject matter described
herein;
Figure 5 is a block diagram illustrating an exemplary transcoder-free operation (TrFO)
over Ethernet protocol stack that may be implemented in a media gateway according
to an embodiment of the subject matter described herein;
Figure 6 is a block diagram of a media gateway including an Ethernet switching fabric
for implementing transcoder-free operation according to an embodiment of the subject
matter described herein;
Figure 7 is a block diagram illustrating an exemplary method for implementing transcoder-free
operation in a media gateway according to an embodiment of the subject matter described
herein; and
Figure 8 is a block diagram illustrating an alternate method for implementing transcoder-free
operation in a media gateway according to an embodiment of the subject matter described
herein.
DETAILED DESCRIPTION OF THE INVENTION
[0017] According to one aspect, the subject matter described herein includes a method for
implementing transcoder-free operation in a media gateway. Figure 3 is a flow chart
illustrating the exemplary steps for implementing transcoder-free operation in a media
gateway according to an embodiment of the subject matter described herein. Referring
to Figure 3, in step 300, lists of media encoding rates and corresponding indices
used by endpoints of a media stream connection are received. These lists may be received
by the control module of the media gateway. The control module may forward the lists
to an internal processor associated with controlling voice processing functions of
the media gateway. In step
302, the internal processor determines whether transcoder-free operation is possible.
Determining whether transcoder-free operation is possible may include examining ingress
and egress codec rates to determine whether the rates are compatible.
[0018] In step
304, if it is determined that transcoder-free operation is not possible, control proceeds
to step
306 where a connection with transcoding is established between endpoints over an Ethernet
switching fabric. In step
304, if it is determined that transcoder-free operation is possible, control proceeds
to step
308 where a transcoder-free operation connection is established between endpoints over
the Ethernet switching fabric in a media gateway using a single DSP to monitor and
vary encoding rates.
[0019] Figure 4 is a block diagram illustrating exemplary components for providing transcoder-free
operation in a media gateway according to an embodiment of the subject matter described
herein. Referring to Figure 4, a codec/DSP
400 implements an IuUP/NbUP protocol stack
402 for both endpoints of a connection and performs radio access bearer sub-flow combination
indicator (RFCI) mapping for a transcoder-free operation connection. A single DSP
400 is used to implement the transcoder-free operation. A second codec, such as that
illustrated in Figure 2, is not utilized. As a result, the solution illustrated in
Figure 4 reduces the resources required to implement transcoder-free operation in
a media gateway. In addition, connections between the endpoints and codec
400 are established over an Ethernet switching fabric, schematically illustrated in Figure
4 by dual arrows
404.
[0020] Figure 5 is a block diagram illustrating protocol stack
402 in more detail. In Figure 5, protocol stack
402 includes a first IuUP/NbUP layer
500 and a first Ethernet interface layer
502 for interfacing with one endpoint of a TrFO connection. In addition, protocol stack
402 includes a second IuUP/NbUP layer
504 and second Ethernet interface layer
506 for interfacing with the other endpoint of a TrFO connection. An RFCI mapping layer
508 maps between codec rates used by the different endpoints of a TrFO connection. It
should be noted that layers
500, 504, and
508 may be implemented by a DSP. It should be noted from Figure 5 that a single DSP
400 is used to implement the IuUP/NbUP layers for each endpoint of a connection as well
as to perform the RFCI mapping. Ethernet interface layers
502 and
506 may be implemented a an Ethernet interface that connects the DSP to an Ethernet switching
fabric. Using a single DSP to perform AMR rate monitoring and RFCI mapping reduces
the resources required to implement TrFO in a media gateway over the implementation
illustrated in Figure 2.
[0021] Figure 6 is a block diagram illustrating a media gateway for implementing transcoder-free
operation according to an embodiment of the subject matter described herein. The architecture
illustrated in Figure 6 corresponds to a media gateway having an Ethernet switching
fabric, as described in commonly-assigned, co-pending
U.S. patent application no. 11/138,990, filed May 26, 2005, the disclosure of which is incorporated herein by reference in its entirety. Referring
to Figure 6, media gateway
600 includes a plurality of voice servers
602 for performing voice processing functions. In the illustrated example, each voice
server
602 includes a voice over packet chip
604, a time slot interconnection
610, CPU
612, DSP
400, and an Ethernet interface
614. Voice over packet chip
604 encapsulates and removes voice information from IP packets and forwards the information
to DSP 400 for further processing. Voice over packet chip
604 may also perform ATM adaptation layer one and layer two functions, respectively.
DSP
400 performs transcoding, echo-cancellation, and other payload translation functions.
According to an aspect of the subject matter described herein, each DSP
400 may implement the IuUP/NbUP protocol stack with RFCI mapping described above. TSI
610 makes on demand connections between voice over IP chip channels, TDM matrix channels
and DSPs. CPU
612 controls the overall operation of each voice server module
602. Ethernet interfaces
614 connect each voice server module
602 with other modules that are connected to an Ethernet switching fabric
616.
[0022] Media gateway
600 also includes broadband network interfaces
617 that connect media gateway to external networks for receiving media packets from
the networks. Broadband network interfaces
617 may include IP network interfaces as well as ATM network interfaces. Each broadband
network interface
617 may include a network processor
618, a connection table
619, and an internal Ethernet interface
620. Network processors
618 control the overall operation of each broadband network interface
617. For example, network processors
618 may control the writing of data to each connection table
618. Each connection table
619 maintains connection data for forwarding media packets to the correct voice server.
Internal Ethernet interfaces
620 connect each broadband network interface
617 to Ethernet switching fabric
616.
[0023] Ethernet switching fabric
616 interconnects voice server
602 and broadband interface
617. In the illustrated example, Ethernet switching fabric
616 includes a plurality of ports, numbered one through five. Five ports are shown for
illustrative purposes only. It is understood that Ethernet switching fabric
616 may include fewer or more than five ports, depending on the number of devices connected
to Ethernet switching fabric
616.
[0024] Media gateway
600 also includes a TDM matrix module
622 for switching TDM time slots between TDM network interfaces
624 and voice servers
602. TDM network interfaces
624 connect media gateway 600 to external TDM devices, such as TDM enabled end offices.
[0025] A control module
626 controls the overall operation of media gateway
600. In the illustrated example, control module
626 includes a TrFO controller
628 for receiving information from CPUs
612 of each voice server module regarding ingress and egress encoding rates and indices,
determining whether TrFO is possible, and instructing voice server module
602 and network interfaces
617 to implement TrFO over Ethernet switching fabric
616. Control module
626 also communicates with an external media gateway controller
630. Media gateway controller
630 controls the establishment of connections by media gateway
600 using a media gateway control protocol, such as MEGACO or MGCP.
[0026] Figure 7 is a block diagram illustrating exemplary steps for achieving TrFO in media
gateway
600 according to one embodiment of the subject matter described herein. Referring to
Figure 7, a first media stream connection (labeled 1) is established between a first
network endpoint, such as a node in RNC/core network
205 that interfaces directly or indirectly with a first mobile phone
700, and a first voice server
602A. A second media stream connection (labeled 2) is established between the second endpoint,
such as a node in RNC/core network
205 that interfaces directly or indirectly with mobile phone
702, and a second voice server
602B. A third media connection (labeled 3) is established between broadband interface
card
617 and voice server card
602B. Once the control module determines a transcoder-free operation is possible, the
control module instructs broadband interface card
617 to replace connection 1 with connection 3. Replacing connection 1 with connection
3 may include instructing broadband interface card
617 to update its connection table
619 to reflect the new connection for the call. In addition, replacing connection 1 with
connection 3 may include instructing voice server
602B to implement the NbUP/IuUP protocol stack and RFCI mapping function described above.
[0027] Tables 1 and 2 shown below illustrate the status of connection table
619 of broadband network interface card
617 before and after transcoder free operation is implemented. Tables 1 and 2 each include
a first column indicating the external or network VPI/VCI value associated with incoming
ATM cells that carry voice. The second column in each table includes a new VPI/VCI
value used internally between the voice server cards and the network interfaces. The
third column includes the voice server MAC address corresponding to the connection.
It can be seen that in Table 1, before transcoder-free operation is established, the
connection to each endpoint includes a separate voice server MAC address. In Table
2, after transcoder free operation is implemented, the voice server MAC address corresponding
to both endpoints of the connection is Ethernet address ETH1, which corresponds to
a single voice server card.
Table 1: Broadband Interface Connection Table Before TrFO
| External VPI/VCI |
New VPI/VCI |
Voice Server MAC Addr. |
| 100/1 |
110/1 |
Eth 0 |
| 100/2 |
110/2 |
Eth 1 |
Table 2: Broadband Interface Connection Table After TrFO
| External VPI/VCI |
New VPI/VCI |
Voice Server MAC Addr. |
| 100/1 |
110/3 |
Eth 1 |
| 100/2 |
110/2 |
Eth 1 |
[0028] An important function performed by a DSP once a TrFO connection is established is
RFCI mapping. In order to perform such mapping, the DSP may maintain separate RFCI
values for each connection endpoint. Tables 3 and 4 shown below are examples of RFI
values that may be maintained by a DSP on a voice server card according to an embodiment
of the subject matter described herein.
Table 3: RFCI Values and Rates for Endpoint A
| Channel Index |
Rate |
| 1 |
12.2k |
| 2 |
10.2k |
| 3 |
7.95k |
| 4 |
6.7k |
Table 3: RFCI Values and Rates for Endpoint B
| Channel Index |
Rate |
| 5 |
12.2k |
| 6 |
10.2k |
| 7 |
7.95k |
| 8 |
6.7k |
[0029] From Tables 1 and 2, the channel index and the corresponding rates for each endpoint
can be determined. Once the DSP knows the indices and corresponding rates, the DSP
can perform mappings between indices used by different endpoints. In the examples
illustrated in Tables 3 and 4, the mappings would be 1-5, 2-6, 3-7, and 4-8.
[0030] Figure 8 is a block diagram illustrating an alternate method for implementing TrFO
in a media gateway according to an embodiment of the subject matter described herein.
Referring to Figure 8, a first media stream connection (labeled 1) is established
between the endpoint that connects to mobile phone
700 and voice server
602A. A second media connection (labeled 2) is established between the endpoint that connects
to mobile phone
702 and voice server
602B. Once TrFO controller
628 (illustrated in Figure 6) that determines transcoder-free operation is possible,
TrFO controller
628 instructs voice server
602A to perform a loop back function and to initiate a connection (labeled 3) with voice
server
602B. Implementing a loop back connection at voice server
602A means that the DSP on voice server
602A is not impacted. Thus, even though the solution illustrated in Figure 8 requires
two voice servers, DSP processing resources are conserved over conventional TrFO implementations
in media gateway, because DSP resources on the voice server where the loop back is
implemented are not used.
[0031] Thus, the subject matter described herein includes methods, systems, and computer
program products for implementing TrFO in media gateway. The subject matter includes
utilizing a single DSP that implements an IbUP/NbUP protocol stack and RFCI mapping
for both ends of a TrFO connection. In addition, the TrFO connection is established
over an Ethernet switching fabric. Because only a single DSP is required, DSP processing
resources are conserved over conventional TrFO implementations. Because an Ethernet
switching fabric is used instead of an ATM switching fabric, the cost and complexity
of the media gateway are reduced.
[0032] It will be understood that various details of the invention may be changed without
departing from the scope of the invention. Furthermore, the foregoing description
is for the purpose of illustration only, and not for the purpose of limitation, as
the invention is defined by the claims as set forth hereinafter.
1. A method for implementing transcoder-free operation in a media gateway, the method
comprising:
a) receiving (300) first and second lists of media encoding rates and corresponding
indices used by first and second media endpoints of a media stream connection;
b) determining (302) whether transcoder-free operation is possible for the media stream
connection based on the first and second lists; and
c) in response to determining that transcoder-free operation is possible for the media
stream connection, establishing (308) a transcoder-free connection over a packet switching
fabric in the media gateway between the first and second media endpoints (700;702)
using a single digital signal processor, DSP, in a first voice server (602A) to monitor
and map between indices and encoding rates used by the first and second endpoints
during the media stream connection,
characterized in that establishing a transcoder-free connection includes establishing a first connection
between the first media endpoint (700) and the first voice server (602A), establishing
a second connection between the second media endpoint (702) and a second voice server
(602B), and replacing the second connection with a third connection between the second
media endpoint (702) and the first voice server (602A), wherein replacing the second
connection with the third connection includes instructing a broadband interface card
in the media gateway to update a connection table to reflect the third connection
and instructing the second voice server (602B) to implement a dual NbUP/IuUP protocol
stack (402) that includes a first NbUP/IuUP layer (500), a second NbUP/IuUP layer
(504), and a radio access bearer sub-flow combination indicator RFCI mapping layer
(508) that maps the encoding rates used by the first and second endpoints.
2. The method of claim 1, wherein receiving (300) first and second lists of media encoding
rates and corresponding indices includes receiving first and second fists of radio
access bearer sub-flow combination indicators, RFCIs, and corresponding media encoding
rates used by the first and second endpoints.
3. The method of claim 1, wherein determining (302) whether transcoder-free operation
is possible includes determining whether the media encoding rates in the first list
are compatible with those in the second list.
4. The method of claim 1, wherein the packet switching fabric includes an Ethernet switching
fabric.
5. The method of claim 1, comprising, after establishing the transcoder-free connection,
performing radio access bearer sub-flow combination indicator, RFCI, mapping for the
connection.
6. A media gateway (600), comprising:
a broadband interface (617) for sending media packets to and receiving media packets
from an external network;
a packet switching fabric (616) for forwarding media packets between the broadband
interface and at least one internal processing resource in the media gateway;
at least one voice server (602) for performing voice processing functions, including
transcoding, for the media packets, wherein the at least one voice server includes
a first voice server (602A) and a second voice server (602B), wherein each of the
first voice server (602A) and the second voice server (602B) includes a single digital
signal processor, DSP, (400) for monitoring and mapping between indices and encoding
rates used by a first media endpoint (700) and a second media endpoint (702) of a
transcoder-free connection; and
a transcoder-free operation controller (628) for establishing the transcoder-free
connection between the broadband interface (617) and the first voice server (602A)
via the switching fabric (616),
characterized in that the transcoder-free operation controller (628) establishes the transcoder-free connection
by establishing a first connection between the first media endpoint (700) and the
first voice server (602A), establishing a second connection between the second media
endpoint (700) and the second voice server (602B), and replacing the second connection
with a third connection between the second media endpoint (702) and the first voice
server (602A), wherein replacing the second connection with the third connection includes
instructing a broadband interface card in the media gateway to update a connection
table to reflect the third connection and instructing the second voice server (602B)
to implement a dual NbUP/IuUP protocol stack (402) that includes a first NbUP/IuUP
layer (500), a second NbUP/IuUP layer (504), and a radio access bearer sub-flow combination
indicator RFCI mapping layer (508) that maps the encoding rates used by the first
and second endpoints.
7. The media gateway (600) of claim 6, wherein the broadband interface (617) comprises
an IP interface.
8. The media gateway (600) of claim 6, wherein the broadband interface (617) comprises
an ATM interface.
9. The media gateway (600) of claim 6, wherein the packet switching fabric (616) comprises
an Ethernet switching fabric.
10. The media gateway (600) of claim 6, wherein the packet switching fabric comprises
an ATM switching fabric.
11. The media gateway (600) of claim 6, wherein the transcoder-free operation controller
(628) is adapted to determine whether transcoder-free operation is possible by examining
the encoding rates used by the first media endpoint and the second media endpoint.
12. The media gateway (600) of claim 6, wherein the first voice server (602B) is adapted
to perform radio access bearer sub-flow combination indicator, RFCI, mapping for the
transcoder-free connection.
13. A computer program product comprising computer executable instructions embodied in
a computer readable medium for performing steps comprising:
a) receiving (300) first and second lists of media encoding rates and corresponding
indices used by first and second media endpoints (700; 702) of a media stream connection;
b) determining (302) whether transcoder-free operation is possible for the media stream
connection based on the first and second lists; and
c) in response to determining that transcoder-free operation is possible for the media
stream connection, establishing (308) a transcoder-free connection over a packet switching
fabric in a media gateway between the first and second media endpoints (700; 702)
using a single digital signal processor, DSP, (400) in a first voice server (602A)
to monitor and map between indices and encoding rates used by the first and second
endpoints during the media stream connection,
characterized in that establishing a transcoder-free connection includes establishing a first connection
between the first media endpoint (700) and the first voice server (602A), establishing
a second connection between the second media endpoint (702) and a second voice server
(602B), and replacing the second connection with a third connection between the second
media endpoint (702) and the first voice server (602A), wherein replacing the second
connection with the third connection includes instructing a broadband interface card
in the media gateway to update a connection table to reflect the third connection
and instructing the second voice server (602B) to implement a dual NbUP/IuUP protocol
stack (402) that includes a first NbUP/IuUP layer (500), a second NbUP/IuUP layer
(504), and a radio access bearer sub-flow combination indicator RFCI mapping layer
(508) that maps the encoding rates used by the first and second endpoints.
1. Verfahren zum Implementieren des Transcoder-freien Betriebs eines Media Gateways,
das Folgendes umfasst:
(a) Empfangen (300) einer ersten und einer zweiten Liste von Medien-Kodierraten und
zugehörigen Indizes, die von einem ersten und einem zweiten Medien-Endpunkt einer
Medien-Datenstromverbindung verwendet werden;
(b) Ermitteln (302), ob Transcoder-freier Betrieb für die Medien-Datenstromverbindung
auf Grundlage der ersten und der zweiten Liste möglich ist; und
(c) Einrichten (308), in Antwort auf das Ermitteln, dass der Transcoder-freie Betrieb
für die Medien-Datenstromverbindung möglich ist, einer Transcoder-freien Verbindung
über eine Paketvermittlungsleitung in dem Media Gateway zwischen dem ersten und dem
zweiten Medien-Endpunkt (700; 702) durch einen einzelnen digitalen Signalprozessor,
DSP, in einem ersten Voiceserver (602A), um Indizes und Kodierraten zu überwachen
und auf einander abzubilden, die von dem ersten und dem zweiten Endpunkt während der
Medien-Datenstromverbindung verwendet werden,
dadurch gekennzeichnet, dass das Einrichten einer Transcoder-freien Verbindung Folgendes umfasst:
Einrichten einer ersten Verbindung zwischen dem ersten Medien-Endpunkt (700) und dem
ersten Voiceserver (602A), Einrichten einer zweiten Verbindung zwischen dem zweiten
Medien-Endpunkt (702) und einem zweiten Voiceserver (602B) und Ersetzen der zweiten
Verbindung mit einer dritten Verbindung zwischen dem zweiten Medien-Endpunkt (702)
und dem ersten Voiceserver (602A), wobei das Ersetzen der zweiten Verbindung mit der
dritten Verbindung das Anweisen einer Breitband-Schnittstellenkarte in dem Media Gateway,
eine Verbindungstabelle zu aktualisieren, um die dritte Verbindung wiederzugeben,
und das Anweisen des zweiten Voiceservers (602B), einen dualen NbUP/IuUP-Protokollstapel
(402) zu implementieren, der eine erste NbUP/IuUP-Schicht (500), eine zweite NbUP/IuUP-Schicht
(504) und eine Mapping-Schicht (508) für Radio Access Bearer Sub-Flow-Combination-Indikatoren,
RFCI, umfasst, welche die Kodierraten abbildet, die von dem ersten und dem zweiten
Endpunkt verwendet werden.
2. Verfahren nach Anspruch 1, wobei das Empfangen (300) der ersten und der zweiten Liste
von Media-Kodierraten und zugehörigen Indizes das Empfangen einer ersten und einer
zweiten Liste von Radio Access Bearer Sub-Flow-Combination-Indikatoren, RFCI, und
zugehöriger Medien-Kodierraten umfasst, die von dem ersten und dem zweiten Endpunkt
verwendet werden.
3. Verfahren nach Anspruch 1, wobei das Ermitteln (302), ob ein Transcoder-freier Betrieb
möglich ist, das Ermitteln umfasst, ob die Media-Kodierraten in der ersten Liste mit
denen in der zweiten Liste vereinbar sind.
4. Verfahren nach Anspruch 1, wobei die Paketvermittlungsleitung eine Ethernet-Vermittlungsleitung
umfasst.
5. Verfahren nach Anspruch 1, das nach dem Einrichten der Transcoder-freien Verbindung
das Ausführen von Mapping mit Radio Access Bearer Sub-Flow-Combination-Indikatoren,
RFCI, für die Verbindung umfasst.
6. Media Gateway (600), das Folgendes umfasst:
eine Breitbandschnittstelle (617) zum Versenden von Medien-Paketen an und Empfangen
von Medien-Paketen von einem externen Netzwerk;
eine Paketvermittlungsleitung (616) zum Weiterleiten von Medien-Paketen zwischen der
Breitbandschnittstelle und mindestens einer internen Verarbeitungsressource in dem
Media Gateway;
Mindestens einen Voiceserver (602) zum Ausführen von Sprach-Verarbeitungsfunktionen
einschließlich Transkodierung, für die Medien-Pakete, wobei der mindestens eine Voiceserver
einen ersten Voiceserver (602A) und einen zweiten Voiceserver (602B) umfasst, wobei
sowohl der erste Voiceserver (602A) als auch der zweite Voiceserver (602B) einen einzigen
digitalen Signalprozessor, DSP, (400) zum Überwachen und Abbilden zwischen Indizes
und Kodierraten umfasst, die von einem ersten Medien-Endpunkt (700) und einem zweiten
Medien-Endpunkt (702) einer Transcoder-freien Verbindung verwendet werden; und
eine Transcoder-freie Betriebssteuerung (628) zum Einrichten der Transcoder-freien
Verbindung zwischen der Breitbandschnittstelle (617) und dem ersten Voiceserver (602A)
über die Vermittlungsleitung (616),
dadurch gekennzeichnet, dass
die Transcoder-freie Betriebssteuerung (628) die Transcoder-freie Verbindung einrichtet,
indem eine erste Verbindung zwischen dem ersten Medien-Endpunkt (700) und dem ersten
Voiceserver (602) eingerichtet wird, eine zweite Verbindung zwischen dem zweiten Medien-Endpunkt
(702) und dem zweiten Voiceserver (602B) eingerichtet wird und die zweite Verbindung
mit einer dritten Verbindung zwischen dem zweiten Medien-Endpunkt (702) und dem ersten
Voiceserver (602A) ersetzt wird, wobei das Ersetzen der zweiten Verbindung mit der
dritten Verbindung das Anweisen einer Breitbandschnittstellenkarte in dem Media Gateway,
so dass eine Verbindungstabelle aktualisiert wird, um die dritte Verbindung widerzuspiegeln,
und das Anweisen des zweiten Voiceservers (602B) umfasst, einen dualen NbUP/IuUP-Protokollstapel
(402) zu implementieren, der eine erste NbUP/IuUP-Schicht (500), eine zweite NbUP/IuUP-Schicht
(504) und eine Mapping-Schicht für Radio Access Bearer Sub-Flow-Combination-Indikatoren,
RFCI, umfasst, die die Kodierraten abbildet, die von dem ersten und dem zweiten Endpunkt
verwendet werden.
7. Media Gateway (600) nach Anspruch 6, wobei die Breitbandschnittstelle (617) eine IP-Schnittstelle
umfasst.
8. Media Gateway (600) nach Anspruch 6, wobei die Breitbandschnittstelle (617) eine ATM-Schnittstelle
umfasst.
9. Media Gateway (600) nach Anspruch 6, wobei die Paketvermittlungsleitung (616) eine
Ethernet-Vermittlungsleitung umfasst.
10. Media Gateway (600) nach Anspruch 6, wobei die Paketvermittlungsleitung eine ATM-Vermittlungsleitung
umfasst.
11. Media Gateway (600) nach Anspruch 6, wobei die Transcoder-freie Betriebssteuerung
(628) geeignet ist, zu ermitteln, ob der Transcoder-freie Betrieb möglich ist, indem
die Kodierraten untersucht werden, die von dem ersten Medien-Endpunkt und dem zweiten
Medien-Endpunkt verwendet werden.
12. Media Gateway (600) nach Anspruch 6, wobei der erste Voiceserver (602B) geeignet ist,
Mapping durch Radio Access Bearer Sub-Flow-Combination-Indikatoren, RFCI, für die
Transcoder-freie Verbindung auszuführen.
13. Computerprogramm-Produkt, das durch Computer ausführbare Befehle umfasst, die in einem
Computer-lesbaren Medium ausgeführt sind, um Schritte auszuführen, die Folgendes umfassen:
(a) Empfangen (300) einer ersten und einer zweiten Liste von Medien-Kodierraten und
zugehörigen Indizes, die von einem ersten und einem zweiten Medien-Endpunkt (700;
702) einer Medien-Datenstromverbindung verwendet werden;
(b) Ermitteln (302), ob Transcoder-freier Betrieb für die Medien-Datenstromverbindung
auf Grundlage der ersten und der zweiten Liste möglich ist; und
(c) Einrichten (308), in Antwort auf das Ermitteln, dass der Transcoder-freie Betrieb
für die Medien-Datenstromverbindung möglich ist, einer Transcoder-freien Verbindung
über eine Paketvermittlungsleitung in einem Media Gateway zwischen dem ersten und
dem zweiten Medien-Endpunkt (700; 702) durch einen einzelnen digitalen Signalprozessor,
DSP, (400) in einem ersten Voiceserver (602A), um Indizes und Kodierraten zu überwachen
und auf einander abzubilden, die von dem ersten und dem zweiten Endpunkt während der
Medien-Datenstromverbindung verwendet werden,
dadurch gekennzeichnet, dass das Einrichten einer Transcoder-freien Verbindung Folgendes umfasst:
Einrichten einer ersten Verbindung zwischen dem ersten Medien-Endpunkt (700) und dem
ersten Voiceserver (602A), Einrichten einer zweiten Verbindung zwischen dem zweiten
Medien-Endpunkt (702) und einem zweiten Voiceserver (602B) und Ersetzen der zweiten
Verbindung mit einer dritten Verbindung zwischen dem zweiten Medien-Endpunkt (702)
und dem ersten Voiceserver (602A), wobei das Ersetzen der zweiten Verbindung mit der
dritten Verbindung das Anweisen einer Breitband-Schnittstellenkarte in dem Media Gateway,
eine Verbindungstabelle zu aktualisieren, um die dritte Verbindung wiederzugeben,
und das Anweisen des zweiten Voiceservers (602B), einen dualen NbUP/IuUP-Protokollstapel
(402) zu implementieren, umfasst, der eine erste NbUP/IuUP-Schicht (500), eine zweite
NbUP/IuUP-Schicht (504) und eine Mapping-Schicht (508) für Radio Access Bearer Sub-Flow-Combination-Indikatoren,
RFCI, umfasst, welche die Kodierraten abbildet, die von dem ersten und dem zweiten
Endpunkt verwendet werden.
1. Procédé pour mettre en oeuvre un fonctionnement sans transcodeur dans une passerelle
média, le procédé comprenant :
a) recevoir (300) de première et seconde listes de taux d'encodage de médias et d'indices
correspondants utilisés par de premier et second points d'extrémité médias d'une connexion
de flux médias ;
b) déterminer (302) si un fonctionnement sans transcodeur est possible pour la connexion
de flux médias sur la base des première et seconde listes ; et
c) en réponse à la détermination qu'un fonctionnement sans transcodeur est possible
pour la connexion de flux médias, établir (308) une connexion sans transcodeur sur
une matrice de commutation de paquets dans la passerelle média entre les premier et
second points d'extrémité médias (700 ; 702) en utilisant un processeur de signaux
numériques, DSP, unique dans un premier serveur vocal (602A) pour surveiller et effectuer
un mappage entre des indices et des taux de codage utilisés par les premier et second
points d'extrémité lors de la connexion de flux médias,
caractérisé en ce que l'établissement d'une connexion sans transcodeur comprend :
établir une première connexion entre le premier point d'extrémité média (700) et le
premier serveur vocal (602A), établir une seconde connexion entre le second point
d'extrémité média (702) et un second serveur vocal (602B), et remplacer la seconde
connexion par une troisième connexion entre le second point d'extrémité média (702)
et le premier serveur vocal (602A), dans lequel le remplacement de la seconde connexion
par la troisième connexion comprend de donner l'ordre à une carte d'interface à large
bande dans la passerelle média de mettre à jour une table de connexion pour refléter
la troisième connexion, et de donner l'ordre au second serveur vocal (602B) de mettre
en oeuvre une pile de protocoles doubles NbUP/luUP (402) qui comprend une première
couche NbUP/luUP (500), une seconde couche NbUP/luUP (504), et une couche de mappage
d'indicateurs de combinaison de sous-flux de support d'accès radio, RFCI, (508) qui
mappe les taux de codage utilisés par les premier et second points d'extrémité.
2. Procédé selon la revendication 1, dans lequel la réception (300) de première et seconde
listes de taux de codage de médias et d'indices correspondants comprend de recevoir
de première et seconde listes d'indicateurs de combinaison de sous-flux de support
d'accès radio, RFCI, et de taux de codage de médias correspondants utilisées par les
premier et second points d'extrémité.
3. Procédé selon la revendication 1, dans lequel la détermination (302) pour savoir si
un fonctionnement sans transcodeur est possible comprend de déterminer si les taux
de codage de médias dans la première liste sont compatibles avec ceux de la seconde
liste.
4. Procédé selon la revendication 1, dans lequel la matrice de commutation de paquets
comprend une matrice de commutation Ethernet.
5. Procédé selon la revendication 1, comprenant, après avoir établi la connexion sans
transcodeur, d'effectuer un mappage d'indicateurs de combinaison de sous-flux de support
d'accès radio, RFCI, pour la connexion.
6. Passerelle de média (600), comprenant :
une interface à large bande (617) pour envoyer des paquets médias à un réseau externe
et recevoir des paquets médias à partir d'un réseau externe ;
une matrice de commutation de paquets (616) pour transmettre des paquets médias entre
l'interface à large bande et au moins une ressource de traitement interne de la passerelle
média ;
au moins un serveur vocal (602) pour exécuter des fonctions de traitement vocal, y
compris un transcodage, pour les paquets médias, dans lequel ledit au moins un serveur
vocal comprend un premier serveur vocal (602A) et un second serveur vocal (602B),
dans lequel chacun du premier serveur vocal (602A) et du second serveur vocal (602B)
comprend un processeur de signaux numériques, DSP, unique (400) pour surveiller et
effectuer un mappage entre des indices et des taux de codage utilisés par un premier
point d'extrémité média (700) et un second point d'extrémité média (702) d'une connexion
sans transcodeur ; et
un contrôleur de fonctionnement sans transcodeur (628) pour établir la connexion sans
transcodeur entre l'interface à large bande (617) et le premier serveur vocal (602A)
par l'intermédiaire de la matrice de commutation (616),
caractérisée en ce que le contrôleur de fonctionnement sans transcodeur (628) établit la connexion sans
transcodeur en établissant une première connexion entre le premier point d'extrémité
média (700) et le premier serveur vocal (602A), en établissant une seconde connexion
entre le second point d'extrémité média (702) et le second serveur vocal (602B), et
en remplaçant la seconde connexion par une troisième connexion entre le second point
d'extrémité média (702) et le premier serveur vocal (602A), dans laquelle le remplacement
de la seconde connexion par la troisième connexion comprend de donner l'ordre à une
carte d'interface à large bande dans la passerelle média de mettre à jour une table
de connexion pour refléter la troisième connexion, et de donner l'ordre au second
serveur vocal (602B) de mettre en oeuvre une pile de protocoles doubles NbUP/IuUP
(402) qui comprend une première couche NbUP/IuUP (500), une seconde couche NbUP/IuUP
(504), et une couche de mappage d'indicateurs de combinaison de sous-flux de support
d'accès radio, RFCI, (508) qui mappe les taux de codage utilisés par les premier et
second points d'extrémité.
7. Passerelle média (600) selon la revendication 6, dans laquelle l'interface à large
bande (617) comprend une interface IP.
8. asserelle média (600) selon la revendication 6, dans laquelle l'interface à large
bande (617) comprend une interface ATM.
9. Passerelle média (600) selon la revendication 6, dans laquelle la matrice de commutation
de paquets (6116) comprend une matrice de commutation Ethernet.
10. Passerelle média (600) selon la revendication 6, dans laquelle la matrice de commutation
de paquets comprend une matrice de commutation ATM.
11. Passerelle média (600) selon la revendication 6, dans laquelle le contrôleur de fonctionnement
sans transcodeur (628) est conçu pour déterminer si un fonctionnement sans transcodeur
est possible en examinant les taux de codage utilisés par le premier point d'extrémité
média et le second point d'extrémité média.
12. Passerelle média (600) selon la revendication 6, dans laquelle le premier serveur
vocal (602A) est conçu pour effectuer un mappage d'indicateurs de combinaison de sous-flux
de support d'accès radio, RFCI, pour la connexion sans transcodeur.
13. Produit de programme informatique comprenant des instructions exécutables par ordinateur
incorporées dans un support lisible par ordinateur pour effectuer les étapes consistant
à :
a) recevoir (300) de première et seconde listes de taux d'encodage de médias et d'indices
correspondants utilisés par de premier et second points d'extrémité médias (700 ;
702) d'une connexion de flux médias ;
b) déterminer si un fonctionnement sans transcodeur est possible pour la connexion
de flux médias sur la base des première et seconde listes ; et
c) en réponse à la détermination qu'un fonctionnement sans transcodeur est possible
pour la connexion de flux médias, établir (308) une connexion sans transcodeur sur
une matrice de commutation de paquets dans la passerelle média entre les premier et
second points d'extrémité médias (700 ; 702) en utilisant un processeur de signaux
numériques, DSP, unique dans un premier serveur vocal (602A) pour surveiller et effectuer
un mappage entre des indices et des taux de codage utilisés par les premier et second
points d'extrémité lors de la connexion de flux médias,
caractérisé en ce que l'établissement d'une connexion sans transcodeur comprend :
établir une première connexion entre le premier point d'extrémité média (700) et le
premier serveur vocal (602A), établir une seconde connexion entre le second point
d'extrémité média (702) et un second serveur vocal (602B), et remplacer la seconde
connexion par une troisième connexion entre le second point d'extrémité média (702)
et le premier serveur vocal (602A), dans lequel le remplacement de la seconde connexion
par la troisième connexion comprend de donner l'ordre à une carte d'interface à large
bande dans la passerelle média de mettre à jour une table de connexion pour refléter
la troisième connexion et de donner l'ordre au second serveur vocal (602B) de mettre
en oeuvre une pile de protocoles doubles NbUP/luUP (402) qui comprend une première
couche NbUP/luUP (500), une seconde couche NbUP/luUP (594), et une couche de mappage
d'indicateurs de combinaison de sous-flux de support d'accès radio, RFCI, (508) qui
mappe les taux de codage utilisés par les premier et second points d'extrémité.